Hydraulic telecontrol device



April 17, 1945. CONWAY 2,373,745

- HYDRAULIC TELE-CONTROL DEVICE Filed March so, 1942 25heets-Sheet L1 H.G; CONWAY HYDRAULIC TELE-CONTROL DEVICE April 17, 1945.

Filed March 50, 1 942 2 Sheets-Sheet 2 Patented Apr. 17, 1 945 UNITE-DSTATES PATENT OFFICE HYDRAULIC rmLEcoN'raoL nnvrcn Hugh Graham Conway,Warrlngton, England, as- T signor to Aeronautical & Mechanical Invest--ments Limited, a British company Application March30, 1942, Serial No.436,909

In Great Britain April 2, 1941 This invention comprises improvements inor relating to hydraulic tele-control devices.

- A type of.hydraulic tele-control apparatus is known in which atransmitting station comprises two cylinders and pistons connectedrespectively to two pipe lines and a receiving station comprises twoother cylinders and pistons into which the pipe hnes deliver so that thereceiving pair of pistons are forced to copy the movements of thetransmitting pair. The pistons being connected by appropriate links tolevers mounted on the transmitting and receivingapparatus, movement ofthe lever at the transmitting end will be copied by the-movement of thelever at the receiving end a of the apparatus.

' In apparatus of the kind described it is only ing to this inventionthe system comprises three transmission pipes and three compressiondepossible to transmit motion in one phase, that is to say, a to-and-fromotion, but in many'case'sin' aircraft, members are mounted so asto havea universal movement-about a centre and thus to be capable of a.compound movement. In other .cases .there may be instances where it isdesirable to transmit desired movements to or from more than'one controlmember. To enable such cases tobe met the present invention contemplateswhatmay be described as a polyphase hydraulic trans g n.

The present invention tele-controlsystem the combination of three ormore transmission pipes connected at one end of comprises in a hydraulicthe system to a transmitting (or receiving) station having compressiondevices and a sing'lea-ctuating member with a compound freedom ofmovement operatively connected to the compression devices so that thephases of'movement .oi the actuating member correspond to phases ofliquid movement in the pipes, said pipes being connected at the otherend to a receiving station (or transmitting station. if thefirst-mentioned end '01. the system is the receiving end) said stationhaving compression devices and one or more actuating members linked tothe compression devices so that their phases of movement are compelledto correspond to the phases of movement of the actuating. member at theother station.

It is to be understood that the expressions one end of the system andthe other end of the system are to be taken broadly as meaning theoperative ends of the system for the purpose of the tele-control underconsideration. There may 'be branches in such a system or the pipes mayrun beyond thefen {for purposes special to a particular installation.For example, it is kmwn that a single phase system may have two or moretransmitting stations and it would be within the "Pi s;

vices at the first-mentioned transmitting (or receiving) station and theactuating'member con- 4 sists of a lever pivoted in the centre of thethree compression devices so as to have a universal movement about saidcentre.

- Further features of the invention will appear from the followingdescription, which is given by way of example, of specific embodimentsof apparatus in accordance with the invention.v

1n the drawings- Figure 1 is a diagram of one form of apparatus inaccordance with the invention showing a transmitting and receivingstation and interconnecting Figure 2 is a vertical section through atransmitting apparatus taken on the line 2-2 of Figure 3; I I

Figure 3 is a plan of the same;

Figure 4 is a diagram of one possible alternative system; and.

Figure 5 is a diagrammatic view ternative system.

Referring to Figure 1, I I is a transmitting station and I2 a receivingstation of a hydraulic tele-control apparatusin which the transmittingstation is provided with three cylinders 13, I4, I 5

grouped equidistantly around a central, pivot l6. Upon the pivot l6there is mounted for universal movement an actuating lever l'l having ahandle l8 and, near the pivot, three radial arms I9, 20,2!

which are connected by piston rods 22 to pistons working in thecylinders l3, l4, 15. The cylinders are connected by transmission pipes23, 24, 25 to the receiving station l2. At the receiving station I2 arethree cylinders 26, 21, 28 containing-pistons which are connected byconnecting rods 29 to the three arms 30, ll, .32 of an actuating leverpivotedabout aL-central universal pivot 33 and provided with anupstanding arm-'34 for actuating devices which it is intended tocontrol. Movement of the actuating lever tlin one plane, saythatindicated by the double-headed arrow 35 at of another .al-'

the transmitting station, will cause hydraulic-fluid ,liquid into thecylinder '26 and to cause as much lifting of the lever arm 3| as at thetransmitting station there was depression of the lever arm ll. Thecylinder 26 being disposed on the opposite in the cylinder II to beexpelled or drawn in, ac-

' work over a pin 01 fixed diametrically across the bore of the cylinderII, M or II as the casemay be. This prevents the piston from rotating.Furthermore, on either side of the slot the pistons have flats as shownat 44, Cl and the flatsspan ports 1| in the sides or the cylinders. Theports are covered with filter-gauze II which is exposed t the reservoir4| and through the filter-gauze hydraulic fluid from the reservoir. canenter the side of the pivot 33 from that which the lever arm It occupieswith respect to the pivot It the result.

is that the arm 34 of the lever at the receiving station moves over inan are having the same direction of movement as the leverl1 and to thesame extent. Movement in another plane, such as is indicated by thearrow 36, will corresponding'ly produce movement in the same plane bythe lever 34 as shown by the arrow 31. and, in fact, movement in anyintermediate planes will similarly be copied precisely,.,both indirection and extent.

I It will, of course, be clear that the apparatus as illustrated inFigure 1 is diagrammatic and that all the ordinary means of compensationfor leakage, for variation of temperature'and so forth which maybecalled for in apparatus of this kind should be provided.

The transmitting and receiving stations-are similar to one anotherexcept that the actuatin! lever I! at the transmitting station isprovided with a handle and the corresponding lever-i4 at the receivingstation is provided with means such as a ball joint 38 'to' enable it tobe connected to" any member which it is intended to control. Thedetailed views shown in Figures 2 and 3 of the transmitting station willtherefore serve as a receiving station also.

ports in and thence pass into the space within the cylinders which isprovided by the flats '2, '9. From here the hydraulic fluid has accessthrough passages", 13 to a light lift valve 14 mounted in th ends ofeach of the pistons 83 and held on its seating by a light spring 15. Theeffect is that if, through leakage or fall in temperature, a reductiontakes place in the amount of fluid in the pipes 22, 24, 25 the fluid ismade up from the reservoir 4|, and it is impossible for the fluidpressure in any of the pipes to fall appreciably below atmosphericpressure so that entry of air through any leaks, which would spoiltheoperation is obviated.

In the apparatus described in Figures 1 to 8 the lever at the receivingend precisely copies the movement of the lever at the transmitting end.It is not, however, essential that this should be the case because it ispossible, seeingthat one of the'levers has a compound movement, for themovement at the other end of the system to be provided by two separatelevers, one ofwhich copies movements or the lever at the other end inone phase or plane and theother of which levers copies movements of thelever at the other end in another phase or plane.

Referring to Figure '4, this shows atransmitting station comprisingcylinders ll, l4, II and a I lever l'l similar to the correspondinglynumbered In Figures 2 and 3, 40 represents a casing which I containsaninternal space 4| acting as a liquidre'servoir and provided withafllling cap 42. In the casing are secured three cylinder bodies l3,

' I4, li which correspond to the cylinders of Figure 1' and areconnected by appropriate union joints to pipes 23, 24, 25, The cylinderbodies parts already described and similarly connected to transmissionpipes 23, 24, 24. s 7

At the other end of the system the pipe 23 is connected to a cylinder 80and the pipe 25 to a have flanges 43 about the middle of their lengthwhich abut on the underside of the casing 40 and are clamped thereto bymeans of a clamping plate 44 secured in place by a central setscrew' 45.

' Packing rings 46, 41 surround the joints which are made between theoutsides of the cylinder walls and the casing 40 so that no leakage maytake place from the reservoir-4|. The casing is provided with fixinglugs 48, 49, so that it may be secured in a suitable position, forexample,

close to the pilot's seat in an aircraft.

On top of the casing 40 there is a'central upstanding forked lug' 5| inwhich is pivoted at 52' thecruciform central member 52 of a Hookes 62 topistons 63 one of which is shown in section in Figure 2. The pistons 63are long cylindrical elements provided with packing rings 84, 65. In

' the central portion they are pierced transversely with along slot 68which serves to receive and to i cylinder 8 l The cylinder 44 forms oneof a pair, each of which contains a piston connected by a link 82 to theopposite ends of a lever having an arm 84 for connection to device.Similarly, the cylinder ll forms one of apair connected by links 82 to alever having an arm 46. The other-cylinders of these two pairs, whichare numbered 81', in the drawings are connected to ether and to the line24. The effect is that if the lever ll be rocked about a line whichpasses through its pivot and its connection to the piston in thecylinder l3, the piston-will remain at rest while the pistons inthecylinders l4 and IE will one of them be moved in and the other one out.This will cause movement of the lever 84 at the receiving station whilethe leverjtremains at rest. Alternatively, if the lever II is rockedabout an axis which passes through theiconnection to the piston in thecylinder II then the piston in the cylinder l3 will be moved inconjunction with that, of l4 and the lever '4 will be moved while 86remains at rest.- Therefore the-lever H can be used to control, twolevers at the receiving station;

Alternatively, there-might be'two levers, such as 84, 86 atthetransmitting station which between them control a single lever such asI! at a receiving station. -In this case. it is assumed that the'lever'84 is held at rest or locked when the lever 86 is operated, and thelever 25 is held or locked when lever 84 is operated.

Moreover, instead of a threerphase system as described, it is possible,as shown in Flgur 5, to have at the transmitter fourc'ylinderl ","ll.

common return line 99. The other cylinders 90 and BI are connectedrespectively to the two lines 81 and 98. The lines 01, 98, and 89 areconnected to a receiver of similar construction comprising fourcylinders I00, IOI, I02, and I03 con-, nected to a lever 104. Lines 91and 88 are con- .nected to cylinders I and I03 respectivelyand thecylinders IM and I02 to the common lin 99. Again. there might be flveor, more cylinders, but the simplest embodiment of the invention wouldappear to be that which is illustrated in Figures 1 to 3. I

In the following claims, the expression a station" includes atransmitting station or a receiving station, thus in the case wherethere are two stations the first station may be a transmitting stationand the second station may be a receiving station or vice versa.

I claim:

1. In a hydraulic tele-control system, the com bination of a stationcomprising a member mounted so as to be capable of a compound freedom ofmovement, three compression devices grouped about the membersymmetrically and operatively connected thereto so that movement of themember in any of the directions in which it is free to move producescompression in at least one of the compression devices and correspondingexpansion in the remainder, three pipes connected one to each of thecompression devices and extending to a second station, threefluidaetuated devices at the second station one in communication witheach of the pipes, and a second member at thep'second station pivotedfor rocking with a compound-freedom of movement, the fluid-actuateddevices at the second station being grouped about said second membersymmetrically and operatively connected thereto, whereby movement of themember at one station in any one direction produces correspondingdirection of movement of the member at the other station at least one ofthe members with a compound freedom of movement consisting of a levermounted on a central pivot element for unision devices consisting ofthree parallel cylinders the axes of which are grouped about the centralv versal movement and, the three fluid-comprespivot element, three'pistons being disposed in the cylinders, and connecting rods connectingthe pistons to the lever.

2. In a hydraulic tele-control system, the combination of a stationcomprising a member mounted so as to be capable of a compound freedom ofmovement, three compression devices grouped about the membersymmetrically and operatively connected thereto so that movement of themember in any of the directions in which it is free to move producescompression in at least one of the compression devices and correspondingexpansion in the remainder, three pipes connected one to each of thecompression devices and extending to a second station, threefluid-actuated devices at the second station one in com-- municationwith each of the pipes, and a second member at the second stationpivoted for rocking with a compound freedom of movement, thefluid-actuated devices at the second station being grouped about saidsecond member symmetrically and operatively connected thereto,wherecompound movement without being capable of rotation about an axisextending along the lever, the three'fiuid-compression devicesconsisting of three parallel cylinders the axes of which are groupedabout the Hookes joint, three pistons being disposed in the cylinders,and connecting rods connecting the pistons to the lever.,

3. In a hydraulic tele-control system, the combination of a stationcomprising a single actuating meinber and a mounting therefor such thatthe member has a compound freedom of rocking movement, at least threefluid-compression devices grouped symmetrically about the member andoperatively connected thereto so that rocking movement of the member inany direction corresponds to compression in at least one of thecompression devices and corresponding expantending therefrom to a secondstation, a second station comprising at least three fluid-actuateddevices each in communication with one of said transmission pipes andactuated means operatively connected to the fluid-actuated devices andhan one movement positively capable of more controlled by the uidactuated devices.

4. A hydraulic tele-control system as claimed in claim 3, wherein theactuating member consists of a lever mounted on a central pivot elementfor universal movement and the fluid-compression devices comprisecylinders having axes parallel to one another and grouped about thepivot point, pistons therein, and connecting rods operatively connectingthe pistons to the lever.

5. A hydraulic tele-control system as claimed in claim 3, wherein theactuating member consists of a lever pivoted on a Hooke's joint so as tobe capable of compound movement without being capable of rotation aboutan axis extending along the lever, thefluid-compression devices consistof cylinders having axes'parallel to one another and grouped about theHooke's joint, pistons therein, and connecting rods operativelyconnecting them with the lever.

6. A hydraulictele-control system as claimed in claim 3, wherein thefluid-actuated devices at the second station consist of cylinders andpis- I necting rods.

by movement of the member at one station in any one directions producescorresponding direc- 7. A hydraulic tele-control system as claimed inclaim 3, wherein the fluid-actuated devices at the second stationconsist of two pairs of cylinders and pistons therein and the actuatedmeans consists of a plurality of levers, one lever located between andoperatively connected to thepistons in one pair of fluid-actuatedpistons and cylinders and the other lever lbeing located between anotherpair of cylinders and operatively connected .to the pistons therein sothat one lever is operated by movement of the actuating member in onedirection and the other lever is operated by movement ofthe actuatingmember in another direction two of the three pipes respectivelyconnected with one cylinder of each pair and the third pipe connected toboth of the remaining cylinders.

HUGH GRAHAM CONWAY.

